The Arrows A9 was a Formula One car which the Arrows team used to compete in the 1986 Formula One season. It was powered by the massively-powerful BMW M12/13 turbocharged inline-four engine. Unlike the BMWs used by the Brabham and Benetton teams whose engines were maintained and updated regularly by BMW, the Arrows engines were maintained by Swiss engine guru Heini Mader and were rated as the least powerful of the BMW runners.

Arrows A9

The A9 at the 2012 Goodwood Festival of Speed
Category	Formula One
Constructor	Arrows
Designer(s)	Dave Wass
Predecessor	A8
Successor	A10
Technical specifications
Chassis	Carbon fibre monocoque
Axle track	Front: 1,854 mm (73.0 in) Rear: 1,676 mm (66.0 in)
Wheelbase	2,921 mm (115.0 in)
Engine	BMW M12/13, 1,500 cc (91.5 cu in), inline-four, turbocharged, mid-engine, longitudinally mounted
Transmission	Arrows / Hewland 6-speed manual
Weight	540 kg (1,190 lb)
Fuel	Castrol
Tyres	Goodyear
Competition history
Notable entrants	Barclay Arrows BMW
Notable drivers	17. Christian Danner 18. Thierry Boutsen
Debut	1986 German Grand Prix
Last event	1986 Austrian Grand Prix
Races Wins Poles F/Laps 3 0 0 0
Constructors' Championships	0
Drivers' Championships	0

The A9 was supposed to replace the ageing A8 car, but it turned out to be worse than its predecessor. The new car was the team's first carbon composite chassis, built by British Aerospace but delays in manufacture caused the car to be late. Its lack of performance caused Dave Wass to quit Arrows.^[1]

Because of this, the team stuck with the A8 from the previous season. As a result, the A9 only saw action at three races, at the German and Austrian Grands Prix, in the hands of Thierry Boutsen, in both of these races the car failed to finish after its turbocharger failed.

At the Hungarian Grand Prix teammate Christian Danner raced the A9 but retired after 7 laps with rear suspension failure.

The Arrows team found that the rear end was the major problem with the A9 and for a couple of races it was run with its new front end joined to the rear end of the A8. While this actually improved the performance of the new car, Arrows soon returned to running the older A8 for the balance of the season.^[2]

Arrows finished the season in 10th place, with a single point, earned by Boutsen's teammate Christian Danner in Austria while driving the A8.